This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Brazzein is a sweet protein found in South American fruit plant Pentadiplatra brazzeana Baillon. The protein intereacts with the sweet repector T1R2-T1R3. To understand their biological significance and interaction with the sweet receptor, we need to understand the structures of sweet brazzein and the non-sweet mutants. This gives insight into their function and help understand interaction with the receptor.